In various industrial arts, skilled laborers use a variety of tools that are each designed to perform a unique task. Many laborers carry a full compliment of tools to ensure that they have the necessary tools to complete the job. Unfortunately, a full set of tools is an expensive investment that requires a heavy tool box or other carrying case that may be both cumbersome and difficult to transport.
Prior attempts to combine similar tools into one multi-function tool have generally failed to provide a tool that is equally adept at performing the function of each particular tool. A number of designs merge the functions of an adjustable wrench with a pair of pliers, but the arrangement of the various moving parts limits the utility and ultimately reduces the strength of the tool. For example, U.S. Patent Application Publication 2004/0163505 discloses a combination plies and adjustable wrench that includes a first handle having a fixed jaw and a second handle having a sliding jaw. A pivot pin pivotally connects the first and second handles. An adjustable worm gear in the second handle allows the user to slide the sliding jaw towards or away from to the fixed jaw. However, the worm gear is positioned at the center of the pivotal connection between the first handle and the second handle, which creates two deficiencies in the tool. First, locating the worm gear inside the pivotal connection increases the distance between the pivot point and the two jaw faces, which reduces the amount of gripping leverage that a user can impart when using the tool as a pair of pliers. Second, locating the worm at the center of the pivot point requires that material must be removed from the pivot point to accommodate the worm gear. Because this area of the tool transmits all of the gripping and turning force that the user applies when using the tool, removing material in this area greatly reduces the mechanical strength of the tool. Moreover, the worm at the center of the pivot makes the connection between the two handles difficult to design and manufacture.
As a second example, U.S. Pat. No. 3,798,687 discloses a similar combination adjustable wrench and pliers tool, but the worm gear and shape of the sliding jaw are such that the pivot point for the two handles is located at a distance far enough from the engaging jaw faces to significantly reduce the amount of gripping leverage that may be imparted by the tool.
Finally, U.S. Pat. No. 5,150,488 discloses a similar combination adjustable wrench and pliers tool with the worm gear for driving the adjustable jaw located adjacent from the pivot point. However, the tool uses a locking detent mechanism that is positioned about the pivot point in such a way that requires the removal of a great deal of material from the handles, which increases the distance between the pivot point and the engaging jaw faces. This arrangement weakens the mechanical strength and durability of the tool and reduces the mechanical advantage that the user may impart by the tool.
Recognizing the limitations and shortcomings of the prior art, the present invention represents an improved combination pliers and adjustable wrench that offers solutions to problems presented by prior art designs.